Toner end detection device and method

Abstract

An apparatus and method for detecting an empty condition of toner cartridges containing toner for copiers, fax machines, printers and the like is disclosed. The cartridges may be mounted to a rotary developing device. According to one embodiment, when a toner cartridge has been rotatably positioned to a developing position, an empty condition is detected by emitting light into the toner cartridge and detecting the light coming out of its bottom. To accomplish this detection, a light source and a light sensor are fixedly located near a bottom corner of the toner cartridge at the developing position. Light is emitted into the toner cartridge at a predetermined oblique angle with respect to a side wall of the toner cartridge. Light exits out from the bottom wall if a predetermined amount of toner does not exist in the toner cartridge. Due to the oblique angle, the distance between the light source and the light sensor is substantially reduced and provides an accurate measurement. This reduced distance also results in a smaller end detection system.

What is claimed is: 
     
       1. An end detection system for a duplicating device comprising: a toner cartridge mounted to a rotary developing device, said toner cartridge having a first wall, a second wall and a common edge formed by said first wall and said second wall, at least a portion of said first wall and said second wall adjacent said bottom edge being substantially light transmissive;   a light source located adjacent to said common edge for emitting a predetermined amount of light into said toner cartridge at a predetermined oblique angle with respect to said first wall and towards said second wall; and   a light sensor located adjacent adjacent to said common edge for detecting light exiting from said toner cartridge, said light being detected on only when said toner cartridge is in a substantially empty condition, said light sensor generating an output indicative thereof.   
     
     
       2. The system according to claim 1 wherein said light source and said light sensor are fixedly located at predetermined positions. 
     
     
       3. The system according to claim 2 further comprising: a light emitting controller connected to said light source for controlling said light source; and   a decision unit responsive to the output of said light sensor for detecting whether said substantially empty condition exists when said toner cartridge is in a predetermined position.   
     
     
       4. The system according to claim 3 wherein said toner cartridge is rotatable with rotation of the rotary developing unit and wherein said light emitting controller causes said light source to repeatedly emit said light while said toner cartridge is being rotated, and said light sensor detecting said light at different angular positions of said toner cartridge, said decision unit detecting whether said substantially empty condition exists at each such angular position based upon said output to provide an indication of the amount of toner remaining in the toner cartridge. 
     
     
       5. The system according to claim 3 wherein said light sensor detects light from said light source when said toner cartridge has been positioned at a predetermined angle with respect to said light source. 
     
     
       6. The system according to claim 3 wherein said toner in said toner cartridge has a color that is one of black, yellow, cyan and magenta. 
     
     
       7. The system according to claim 6 further comprising a frequency bandpass filter, said light emitting controller causing said light source to emit said light at a predetermined frequency based upon said color of said toner, said frequency bandpass filter selectively responding to said light of said frequency. 
     
     
       8. The system according to claim 6 wherein said light emitting controller causes said light source to emit said light at a predetermined light intensity based upon said color of said toner. 
     
     
       9. The system according to claim 1 further comprising a vibrating device in operative contact with said toner cartridge for vibrating said toner cartridge to remove toner remaining on inside surfaces of said toner cartridge. 
     
     
       10. The system according to claim 1 wherein said first wall is a side wall of said toner cartridge and said second wall is a bottom wall of said toner cartridge. 
     
     
       11. The system according to claim 3 further comprising a stepping motor connected to said rotary developing device for rotating said toner cartridge, said stepping motor, in response to an output of said decision unit, rotatably positioning said toner cartridge that is in said substantially empty condition to a predetermined retrieval position. 
     
     
       12. The system according to claim 3 further comprising a warning device response to said decision unit for indicating the presence of said substantially empty condition. 
     
     
       13. In a duplicating device, an end detection apparatus comprising: a plurality of toner cartridges mounted to a rotary developing device, each of said toner cartridges having a first wall, a second wall and a common bottom edge formed by said first wall and said second wall, at least a portion of said first wall and said second wall adjacent said bottom edge being substantially light transmissive, each of said toner cartridges being rotatable to a predetermined detection position, the toner cartridge in said detection position being defined as a test toner cartridge;   a light source fixedly located adjacent said test toner cartridge for emitting a predetermined amount of light towards said first wall adjacent said bottom edge at a predetermined oblique angle with respect to said first wall and into said test toner cartridge towards said second wall; and   a light sensor fixedly located adjacent said bottom edge of said second wall for detecting said light exiting from said test toner cartridge, said light being detected only when said toner cartridge is in an empty condition, said light sensor providing an output indicative thereof, each toner cartridge being rotated to said detection position for detecting the presence of said empty condition.   
     
     
       14. The apparatus according to claim 13 further comprising: a stepping motor coupled to said rotary developing device for rotating said rotary developing device and said toner cartridges;   a cartridge information processor for tracking the rotation of said toner cartridges and for generating an output indicating that the test toner cartridge is in said empty condition; and,   a warning indicator connected to said cartridge information processor for indicating said empty condition of said toner cartridge.   
     
     
       15. The apparatus according to claim 13 wherein each of said toner cartridges contains a unique color toner being one of cyan, magenta, block and yellow. 
     
     
       16. The apparatus according to claim 15 wherein said light source emits said light at a predetermined light intensity based upon said unique color. 
     
     
       17. The apparatus according to claim 15 wherein said light source emits said light at a predetermined frequency based upon said unique color. 
     
     
       18. The apparatus according to claim 13 wherein said light source repeatedly emits said light while said test toner cartridge is rotated and said light sensor detects said light at different angular positions of said test toner cartridge to determine an amount of said toner remaining in said test toner cartridge. 
     
     
       19. The apparatus according to claim 13 wherein said light sensor detects said light when said test toner cartridge has been positioned to said detection position. 
     
     
       20. A method of detecting an empty condition in a toner cartridge mounted to a rotary developing apparatus, the toner cartridge having a first wall, a second wall and a common bottom edge formed by said first wall and said second wall, at least a portion of said first wall and said second wall adjacent the bottom edge being substantially light transmissive, comprising the steps of: a. emitting light towards said first wall adjacent said bottom edge at a predetermined oblique angle with respect to said first wall and towards said second wall adjacent said bottom edge;   b. detecting whether light exits from said second wall adjacent said bottom edge, said light exiting when the empty condition exists; and   c. determining whether said toner cartridge is substantially empty based upon step b.   
     
     
       21. The method as recited in claim 20 further comprises the steps of: d. generating a signal indicative of the empty condition of said toner cartridge based upon step c;   e. warning an operator of said empty condition;   f. moving said toner cartridge to a predetermined position for replacement thereof when the empty condition has been detected; and,   g. ascertaining correct placement of a replacement toner cartridge is correctly placed.   
     
     
       22. The method as recited in claim 20 wherein said toner cartridge contains toner of a color that is one of cyan, magenta, yellow and black. 
     
     
       23. The method as recited in claim 22 wherein said light is emitted at a predetermined light intensity based upon said color. 
     
     
       24. The method as recited in claim 22 wherein said light is emitted at a predetermined frequencies based upon said color. 
     
     
       25. The method as recited in claim 24 wherein step b comprises employing a frequency band filter that is selectively responsive to said predetermined frequency. 
     
     
       26. The method as recited in claim 20 wherein step a and said step b are repeatedly performed as said toner cartridge is rotated. 
     
     
       27. The method as recited in claim 20 wherein step a and said step b are performed when said toner cartridge has been rotatably positioned to a predetermined detection position. 
     
     
       28. A method of detecting the status of a plurality of toner cartridges mounted to a rotary developing apparatus, each of the toner cartridges having a first wall, a second wall and a common bottom edge formed by said first wall and said second wall, at least a portion of said first wall and said second wall adjacent the bottom edge being substantially light transmissive, comprising the steps of: a. positioning one of the toner cartridges at a predetermined detection position, said toner cartridge positioned at said predetermined detection position being defined as a test toner cartridge;   b. emitting light towards said first wall adjacent said bottom edge of said test toner cartridge at a predetermined oblique angle with respect to said first wall and towards said second wall adjacent said bottom edge of said test toner cartridge;   c. detecting light exiting from said second wall adjacent said bottom edge of said test toner cartridge, said light exiting when the empty condition exists; and   d. determining whether said test toner cartridge is substantially empty based upon step c.   
     
     
       29. The method as recited in claim 28 wherein each of the toner cartridges contains a toner of a unique color. 
     
     
       30. The method as recited in claim 29 wherein step d further comprises the steps of: e. generating a signal indicative of an empty condition of said test toner cartridge based upon step d;   f. warning an operator of said empty condition;   g. rotating said test toner cartridge to a predetermined position for replacement thereof when the empty condition has been detected; and,   h. ascertaining correct placement of a replacement toner cartridge.   
     
     
       31. The method as recited in claim 30 wherein said signal generated in said step e is further indicative of said color of said toner in said test toner cartridge. 
     
     
       32. A method of determining an amount of toner remaining in a toner cartridge for a rotary developing apparatus, the toner cartridge having a first wall and a second wall, comprising the steps of: a. rotating said toner cartridge to a predetermined angular position;   b. emitting light towards said first wall of said toner cartridge when said toner cartridge has been positioned to said predetermined angular position;   c. measuring the light exiting from said toner cartridge when said toner cartridge has been positioned to said predetermined angular position;   d. rotating said toner cartridge to a different predetermined angular position;   e. repeating said steps a through c for said different predetermined angular position; and   f. determining the amount of the toner remaining in said toner cartridge based upon steps c and d.